Try riding three at once – like the members of the New York chapter of the Black Label Bike Club.

They custom-make their contraptions out of junk and spare parts, creating mutants – like the 6-foot-high “tall bikes” – that bear little resemblance to any 10-speed.

“It’s totally the edge of the impossible, taking garbage and turning it into something functional and unique,” says Paula Zaslavsky, 26, a Black Label member who also works as a messenger and runs after-school programs at the Brooklyn Public Library.

“The bikes make people do a double take. Hearing someone say, ‘Oh my God, where’d you buy that?’ and then saying, ‘We didn’t, we made it,’ is fun, too – but the truth is they’re super-fun to ride, you’re up high and it’s a rush.”

The Black Label Bike Club started off 12 years ago in Minneapolis, building its reputation among the kids there, before spreading to New York two years ago.

Today at 2 p.m., the 20-plus Black Label bikers are putting on a block party in Brooklyn at Stanford Place at Willoughby Avenue, exhibiting their creations and the activities they like to participate in – notably tall bike jousting.

Much like the knights of yore (minus the horses), two riders on tall bikes charge at each other with long PVC pipe poles, trying to knock each other off their mounts.

“People like when we get hurt, they’re really into that. It’s like being gladiators,” says Doyle, a 24-year-old metalworker, artist and undefeated tall-bike jousting champion.

Serious injuries are rare, although Doyle once took a “chunk” out of a guy’s stomach while jousting with nails attached to two-by-fours down in New Orleans – and even admits to getting the occasional “handlebar to the crotch.”

Being that far off the ground might seem like a challenge, but Black Label members say it’s just like riding a regular Schwinn.

“Once you get it moving, you just climb up it, while steering to keep yourself upright,” says Ben, 30, a messenger.

Tall bikes aren’t their only innovation, though.

“We build bikes that pivot, called a swing bike, where you bring the handlebars up to the seat,” says Ben.

“Those take a little bit of practice to ride – you kind of fall down a lot until you get the hang of it.”

Then there’s the “bronco bike,” whose off-center wheels make the rider look like he’s aboard a bucking bronco at a rodeo.

“That one takes a lot of practice,” says Ben. “You have to use your muscles to hold on, but at the same time be kind of like jelly, where you can ride it without being thrown off.”

When you check out the Black Label’s wheels today – which you’ll be allowed to ride – there are a few words to the wise:

“Keep your distance while people are showing off, ride the bikes at your own risk, and have the most fun that you possibly can,” advises Doyle.

A bike group with chapters around the country, Black Label, has come up with some inventive new bikes, with names to match:

Tall bike: a bike that puts its rider several feet off the ground, usually made from multiple bike frames

Small talls: a tall bike made out of two kids’ bikes

Three-wheeled freaks: a bike with three wheels

Meat wagon: a bike with a working barbecue attached

Widow maker: a recumbent bike that’s 4 feet high

Swing bike: a double-hinged bike with handlebars that swing around

Tall chopper: a bike that looks like a Harley because of its two frames – one that’s standing straight up as if in a wheelie, and another frame perpendicular to that with a 12-foot piece of wood (called a fork)